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Mysql 游标示例

Mysql 游标示例

作者: 想象之中丶意料之外 | 来源:发表于2018-06-12 16:21 被阅读0次

    CREATE  PROCEDURE `gk_test`()

    COMMENT '测试数据'  -- 函数注释

    BEGIN

        DECLARE done INT DEFAULT FALSE; -- 定义遍历数据结束标志。非游标变量,需要定义在游标变量前

        DECLARE m_id CHAR(32); -- 定义接收游标数据中id变量

        DECLARE m_or VARCHAR(255); -- 定义接收游标数据中orderno变量

        DECLARE m_c INT(11);  -- 定义接收游标数据中count变量

        DECLARE m_soult CURSOR FOR SELECT `id`, `orderno`, count(*) t FROM hb_shipper_order GROUP BY orderno HAVING t >1;   -- 定义游标变量,即接收查询结果集

        DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;  -- 将结束标志绑定到游标

        OPEN m_soult;    -- 打开游标

        read_loop:LOOP   -- 开始循环。这个是mysql 3种循环中的1种。

            FETCH m_soult INTO m_id,m_or,m_c;   -- 提取游标数据

            IF done THEN   -- 判断,当为true时

                LEAVE read_loop;   -- 跳出循环

            END IF;

            -- 处理事 自己想处理的事

            UPDATE `hb_shipper_waybill` SET

            ordernos = REPLACE (`ordernos`, m_or, CONCAT(m_or,'-2')),

            goodsname = REPLACE (`goodsname`, m_or, CONCAT(m_or,'-2'))

            WHERE `id` IN ( SELECT `waybillid` FROM `hb_shipper_order_waybill_relation` WHERE orderid = m_id);

            UPDATE `hb_shipper_order` SET orderno = CONCAT(m_or,'-2') WHERE id = m_id;

        END LOOP;  -- 结束循环

        -- 关闭游标

        CLOSE m_soult;

    END

    上图:

    DEMO: 2    // 通过 存储过程,处理  copy 数据并处理对应数据关系

    delimiter $$
    DROP PROCEDURE IF EXISTS gk;
    CREATE DEFINER =  PROCEDURE `gk`(IN pname varchar(255))
        COMMENT '测试'
        BEGIN
            DECLARE new_id CHAR(32);
            DECLARE m_id CHAR(32);
            DECLARE new_noids VARCHAR(255);
            DECLARE done INT DEFAULT 0;
            DECLARE m_result CURSOR FOR select id from `xxx`;
            DECLARE m_result2 CURSOR FOR select id from `xxx`;
            DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
            DROP TABLE IF EXISTS `xxx`;
            CREATE TABLE `xxx` (
                    `id` char(32) NOT NULL COMMENT 'ID',
                    `subsystem` char(32) NOT NULL COMMENT '',
                    `name` varchar(20) NOT NULL COMMENT '',
                    `type` varchar(15) NOT NULL COMMENT '',
                    `url` varchar(200) DEFAULT NULL COMMENT '',
                    `icon` varchar(20) DEFAULT NULL COMMENT '',
                    `target` varchar(10) NOT NULL DEFAULT '_self' COMMENT '',
                    `method` mediumtext COMMENT '',
                    `orderby` smallint(3) NOT NULL DEFAULT '0' COMMENT '',
                    `parentid` char(32) NOT NULL DEFAULT '0' COMMENT '',
                    `relateid` char(32) NOT NULL COMMENT '',
                    `isopen` tinyint(1) NOT NULL DEFAULT '1' COMMENT '',
                    `nodeids` varchar(255) DEFAULT NULL COMMENT '',
                    `nodenum` smallint(3) NOT NULL DEFAULT '0' COMMENT '',
                    `createtime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '',
                    `createuser` char(32) NOT NULL DEFAULT '0' COMMENT '',
                    `updatetime` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT '',
                    `udateuser` char(32) NOT NULL DEFAULT '0' COMMENT '',
                    `deleted` tinyint(1) DEFAULT '0' COMMENT '',
                    `status` tinyint(1) NOT NULL DEFAULT '0' COMMENT '',
                    `isdefault` tinyint(1) unsigned NOT NULL DEFAULT '0' COMMENT '',
                    `isdisable` tinyint(1) unsigned NOT NULL DEFAULT '0' COMMENT '',
                    `projecttype` varchar(255) NOT NULL COMMENT '',
                PRIMARY KEY (`id`)
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT;
            INSERT INTO `xxxx` SELECT * FROM `aaa` WHERE `projecttype` = 'T';
            UPDATE `xxx` SET `projecttype` = pname;
            OPEN m_result;
            REPEAT
                    FETCH m_result INTO m_id;
                            SET new_id = UPPER(REPLACE(UUID(),'-',''));
                            UPDATE `xxx` SET `id` = new_id WHERE `id` = m_id;
                            UPDATE `xxx` SET `parentid` = new_id WHERE `parentid` = m_id;
            UNTIL done END REPEAT;
            CLOSE m_result;
            SET done = 0;
            OPEN m_result2;
            REPEAT
                    FETCH m_result2 INTO m_id;
                            SELECT CONCAT(',', GROUP_CONCAT(`id`)) INTO new_noids FROM `xxx` WHERE `parentid` = m_id;
                            UPDATE `xxx` SET `nodeids` = new_noids WHERE `id` = m_id;
            UNTIL done END REPEAT;    
            CLOSE m_result2;
            INSERT INTO `aaa` SELECT * FROM `xxx`;
            DROP TABLE IF EXISTS xxx;
        END $$
    delimiter ;

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